Impact of Soft Palate Extension and Elevation on Pharyngeal Airflow in Cleft Palate Patients: A Computational Fluid Dynamics Study

The aim of the study was to investigate the changes in pharyngeal airflow pressure and velocity in cleft palate patients following palatoplasty with different soft palate lengths and heights using computational fluid dynamics (CFD) analysis. A pathological model of velopharyngeal insufficiency was developed based on computed tomography data from patients with cleft palate. Computational fluid dynamics analysis was performed to simulate soft palate extension and elevation during palatoplasty, and the aerodynamic characteristics of the upper airway and the impact of these modifications on velopharyngeal closure were analyzed. During phonation, airflow velocity in the oropharynx increased above the soft palate and was higher than that below the soft palate when extension was simulated. The maximum airflow velocity was observed in the oropharyngeal airway above the soft palate. However, variations in maximum pressure, minimum pressure, and maximum pressure difference in the upper airway were not correlated with soft palate extension. In contrast, with soft palate elevation, airflow velocity above the soft palate in the oropharynx increased, while airflow velocity below the soft palate in the oral cavity decreased. The airflow pressure below the soft palate remained consistently higher than that above the soft palate in the oropharynx. Both soft palate extension and elevation influence airflow velocity and pressure in the upper airway. However, elevation was more effective in achieving velopharyngeal closure than extension. Computational fluid dynamics analysis could serve as a valuable tool for the virtual design of surgical interventions and for predicting postoperative outcomes in palatoplasty.